On March 1, 1993, Steven Spielberg began production on Schindler's List in Krakow, Poland. Twenty years later, the director reflected on the resonance of the Academy Award-winning drama and reiterated his commitment to preserving the memories of Holocaust survivors.

"Sometimes it seems as if there are still people immune to the notion of empathy, of compassion," Spielberg said at a news conference Wednesday in Pasadena. "People who see disturbing images on media and on television, people who watch, let's say, a clip of random violence or discrimination or bullying on YouTube and stand silent. So many in the world refuse to bear witness and do something about it. And I'm finding that in many cases technology is becoming more of a vehicle of voyeurism than a vehicle for change."

The filmmaker made remarks and took questions at the Chandler School as part of a launch event for the IWitness Video Challenge, which encourages secondary school students to honor the legacy of Schindler’s List by engaging in community service inspired by survivors’ testimonies and showcasing their action in a short video essay. The event was sponsored by the USC Shoah Foundation, which Spielberg founded in 1994, and timed to the release of the best picture Oscar winner's March 5 Blu-ray release.

The director shared the backstory of his thinking before he embarked on making Schindler's List.

"My parents, who weren't involved in the Holocaust, often talked about the Holocaust," he said. "It was a subject that was very open in my formative years, and I saw a lot of documentaries. I was just like a passive witness; I wasn't doing very much about it. I was just taking it all in. … I couldn't believe that something like that could've happened in the 20th century -- it was just unfathomable -- but it did."

When asked about the film's resonance, Spielberg replied that it had a great worldwide impact.

"I still feel that Schindler's List is the film that has made the most amount of material change in the world," he said. "When I went to Poland to start working on Schindler's List, I quickly realized after a couple of days of filming that this just wasn't a natural reflex of my filmmaking instincts -- this was going to be something that was going to change my life."

Since 1994, the Shoah Foundation has compiled more than 51,000 interviews with witnesses to genocide around the globe, and some of those testimonials are viewable on the IWitness student website, the organization said.

"None of us make movies thinking they are going to do anything other than come out on all the other ancillary markets, come out on DVD and come out on television and that's going to be it," Spielberg said. "The shelf life of Schindler's List has renewed my faith that films can do good work in the world, but it's up to people to allow those images to be impressionable, to last and for people to do something about it."

Released in December 1993, Schindler's List grossed more than $320 million worldwide. It went on to win seven Academy Awards, including Spielberg's first Oscar for best director.